Meter.



THOMAS DUNCAN, OF LAFAYETTE, INDIANA.

METER. i

Speccaton of Letters Patent.

Patented Aug. 1, 1905.

Application led January 8, 1902. Serial No. 88,831l

To aZZ whom, t may concern:

Be it known that I, THOMAS DUNCAN, a citi'- zen of the UnitedStates,residing at Lafayette, in the county of Tippecanoe and State ofIndiana, have invented a certain new and useful Improvement in Meters,of which the following is a full, clear, concise, and exact description,reference being had to the accompanying drawing, forming a part of thisspecification.

My invention relates to meters adapted for use in connection withstorage batteries, and has for its object the provision of a meter thatis adapted to rotate at different rates of speed per unit of load orenergy upon variations in the rate of battery discharge and which isadapted to measure in units of watt-hours.

. By means of my invention the meter is caused to operate at anincreased rate of speed per unit of load or energy upon an increase inthe rate of discharge. f

In the use of storage batteries it is Well known that the output of thebattery will always be less than the energy storedtherein and that thebattery loss will increase upon a suliicient increase in the rate ofbattery discharge. For example, (supposing the battery to be aone-hundred-volt battery,) if the battery is charged one hundredthousand watthours at its normal rate-say ten thousand watts per hourfor ten hours-the total discharge at the same rate which can be madeavailable without harm to the battery will not be more than about eightyper cent. of the energy charged into the battery with some makes ofbattery, this battery loss varying with different makes-that is, thebattery will effectively operate at one hundred amperes for eight hours,giving out eight hundred ampere-hours (equivalent to eighty thousandWatt-hours of energy) after having received one thousand ampere-hours,(equivalent to one hundred thousand Watt-hours.) If the rate ofdischarge is increased, the total output will be diminished. Forexample, with certain makes of battery the energy discharged-will not beover about seventy per cent. if the rate is increased to one hundred andforty amperes per hour, sixty per cent. if the rate of discharge isdoubled, and forty per cent. if the rate of discharge is quadrupled. i

I have provided an instrument that is adapted to compensate for thevarying battery losses due to the varying rates of discharge, so thatthe user of the battery may knowwhen the available energy in the batteryis spent. Ordinarily a meter associated with a storage battery that isdischarged at varying rates will indicate the presence of more energyvinthe battery than actually exists. The meter of my invention is alsoadapted to measure in watt-hours the energy that is being stored in thebattery, the meter when thus associated with the charging source ofcurrent being 0peratively dissociated from the means that cause themeter to operate at varying rates of speed per unit of' load or energyat diiferent rates of discharge. p

The meter of my invention is particularly adaptedrfor use in connectionwith motors employed in operating motor-vehicles where the rate ofdischarge is not constant, but is liable to be changed at any time. Thepreferred means for causing this variation in the rate of operation ofthe meter consists in the provision of a variable load that isautomatically controlled by means subject to the variable volume ofcurrent flowing from the battery.

This load is preferably in the form of an electromagnetic drag actingupon a disk coupled with the rotating element of the meter and having awinding subject to the pressure of the battery. This electromagnet isalso provided with a winding in series with the battery which acts inopposition to the shuntwinding in a degree dependent upon the I'iow ofcurrent or rate of discharge to decrease the force of the drag andpermit the speed of the disk and rotating element of the meter to'in#crease as the rate of discharge increases.

I Will explain my invention more fully by reference to the accompanyingdrawing, which is a diagrammatic view of a storagebattery system withthe meter of my invention associated therewith.

In the drawing a storage battery 1 is illustrated, having mains 2 and 3.The main 2 is provided with bifurcated branches't, terminating incontacts 6 and 7, while the main' 3 terminates in a pivotal mounting 8,upon which a switch-blade 9 of a switch lO is secured. A secondswitch-blade l1 of the switch lOis also placed upon a pivotal mountingl2. Terminals of a charging-circuit 13 and 14E are illustrated.Terminals l5 and 16 of conductors leading to translating means, as themotor of a motor-Vehicle, are also illustrated. When the switch 10 isthrown to the left, the charging-machine or source of current is throwninto circuit with the storageV battery. When y the switch is thrown tothe right', the storage battery is thrown into circuit with thetranslating means.

I have illustrated a meter having a currentwinding included in the main2, this currentwinding being subdivided into coils 17 17. The meter isalso provided with a pressurewinding 18, included in bridge between thebattery7 leads or mains. These windings of the meter are constantly incircuit with the battery irrespective of its association with thecharging-machine or the translating means. rl`he meter-winding 18 ispreferably in the form of an armature and is mounted upon a spindle 19,at the lower end of which is provided adisk 20, arranged within thefields ot a damping-electromagnet 21 and a permanent magnet 22. Theshaft 19 also carries the commutator 23, against which bear brushes 2424, that serve to include the armature of the meter in circuit, achoking and adjusting resistance 25 being also included in circuit withthe armature.

The meter is provided with gearing at its upper end to actuate themeasuring-index 26, which by cooperation with a suitable reading- Scaleserves to indicate the amount of energy stored in the battery incharging and remaining in thebattery in discharging.

The meter illustrated is adapted to measure in units of kilowatt-hours.

The winding ofthe electromagnet 21 is pret'- erably included in serieswith a clicking' and adjusting resistance 27 and in bridge of thebattery mains or leads to be subject to the battery-potential. The coreoi' the magnet 21 is provided with a winding 28, that is connected incircuit with the branch conductor 5. When the switch is thrown to theleft in charging the battery, both windings of the magnet 21 are cut outof circuit, the metercircuit being completed by way of the branchconductor 4. To compensate for the load removed from the'meter by theexclusion of the windings of the magnet 21 from circuit, I provide atorque-reducing coil 29, that is included in circuit with the armaturewhen the switch is thrown to the left, so that a reduced torqueaccompanies the reduced load when the energy that is being stored in thebattery is measured. When the switch is thrown to the right, the branchconductor 4 is disconnected, whereupon the meter-circuit is completed byway of the conductor 5 and the supplemental magnet-winding 28.

With this adjustment oi' the switch 10 the torque-reducing resistance 29is cnt out of circuit, both windings of the electromagnet 21 being thenincluded in circuit. In either adjustment of the switch 10, as thedampingdisk 20 is subject to the iniiuence of the magnet 22 ofpermanently uniform strength, the meter measures in units of watt-hours.The force of the electromagnetic drag, due to the magnet 21, dependsupon the diierence in potential between the battery-terminals, and asthat difference becomes less and less as the discharge proceeds theconsequent drag will also decrease. The winding 28 exerts an opposing orneutralizing eii'ect upon the main shunt-winding of the magnet 21,effecting a corresponding reduction in the drag. As the magnetizationdue to this winding 28 varies with the amount oi: current l'lowing lromthe battery, the degree that the braking action is reduced will dependupon the rate oli battery discharge. A large liow of current due to ahigh rate of discharge will obviously decrease the drag to aproportionately greater extent than a smaller ilow of current due to alesser rate ol. discharge, and by proper proportioning and calibrationthe meter may in this manner be made to compensate for the varyingineiiiciency oi the battery throughout its entire range of operation.

Thilo l have herein shown and particularly described the preferredembodiment of my invention, it is obvious that changes may readily bemade without departing from the spirit thereof` and l do not wish,therefore, to be limited to the precise disclosures herein set forth;but,

Having thus described my invention, l. claim as new and desire to secureby Letters Patent 1. The combination with a storage battery, of awatt-hour meter for measuring energy discharged, and means for operatingthe meter at varying rates of speed per unit ol load or energy,according to varying rates oi discharge, substantially as described.

2. The combination with a storage battery, oi' a watt-hour meter formeasuring energy discharged` and means for operating the meter atincreased rates oi speed per nnitoi load or energy upon correspondingincreases in the rate of discharge of the battery, substantiall y asdescribed.

3. The combination with a storage battery, of a watt-hour meter formeasuring energy discharged, a load for the meter, and means fordecreasing the load upon an increase in the rate oi' discharge toincrease the rate of operation of the meter per unit oi load or energy,substantially as described.

4. The combination with a storage battery, oi' a watt-hour meter lormeasuring battery discharge, provided with a damping-disk, a magnetwithin whose iield the said disk is located, a permanent dam ping-magnetfor causing the meter to measure in units oli' watthours, and means fordecreasing the force ol the lield of the lirst aforesaid magnet upon anincrease in the rate oi 'cattery discharge to increase the rate ofoperation ol" the meter per unit of load or energy, substantially asdescribed.

5. The combination with a storage battery, of a meter Yfor measuringbattery discharge, provided with a dam ping-disk, a magnet within whosefield the said disk is located, and having a winding in circuit with thebattery for producing a counter-magnetizing effect to reduce the forceof the magnet to decrease the load upon the meter and increase the rateof operation of the meter per unit of load or energy, and a permanentdamping-magnet, substantially as described.

6. The combination with a storage battery, of a meter for measuringbattery discharge, provided with a damping-disk, a magnet with'- inwhose iield the said disk .is located, a winding for the magnet subjectto thebattery-potential, a second winding for the magnet opposing thepressure-winding and included in series with a battery, whereby theopposing effect is increased upon an increase in the rate of batterydischarge to lessen the load upon the meter to cause the meter tooperate at an increased rate of speed pervunit of load or energy, and apermanent damping-magnet for causing the meter to measure in units ofwatthours, substantially as described..

7. The combination with a storage battery, of an electric meter providedwith an electromagnetic drag energized by a winding in series with thebattery, and a permanent magnetic drag, substantially as described.

8. The combination with a storage battery, of a meter for measuringbattery discharge, provided with adamping-disk, a magnet within whoseiield the said disk is located, a winding for the magnet subject to thebattery-potential, a second winding for the magnet opposing thepressure-winding and included in series with a battery, whereby theopposing eEect is increased upon an increase in the rate of batterydischarge to lessen the load upon the meter to cause the meter tooperate at an increased rate of speed per unit of load or energy, apermanent damping-magnet for causing the meter to measure inunits ofwatthours, means for excluding the windings of the said electromagnetfrom' circuit when the storage battery is connected with the charging--provided with a damping-disk, a magnet within whose iield the said diskis located, a winding for the magnet subject to the battery-potential, asecond winding for the magnet opposing the pressure-Winding and includedin series with a battery, whereby the opposing effect is increased uponan increase in the rate of battery discharge to lessen the load upon themeter, to cause the meter to operate at an increased rate of speed perunit of load or enery, a permanent damping-magnet for causing the meterto measure in units of watthours, means for excluding the windings ofthe said electromagnetfrom circuit when the storage battery is connectedwith the charging-machine, means' for including the said windings incircuit when the storage battery is connected with the translatingmeans, and

means for reducing the torque of the meter when the battery is connectedwith the charging-machine to compensate for the removal of the saidmagnet-windings when the battery is connected with the charging-machine,substantially as described.

l0. The combination with a storage battery, of a meter for measuringbattery discharge, provided with a damping-disk, a magnet within whosefield the said disk is located, a winding Jfor the magnet subject to thebattery-potential, a second winding forthe magnet op-l posing thepressure-winding and included in series with a battery, whereby theopposing effect is increased upon an increase in the rate of batterydischarge to lessen the load upon the meter to cause the meter tooperate at an increased rate of speed per unit of load or energy,- apermanent damping-magnet for causing the meter to measure in units ofwatthours, means for excluding the windings of the said electromagnetfrom circuit when the storage battery is connected with thecharging-machine, means for including the said windings in circuit whenthe storage battery is connected with the translating means, atorque-reducing resistance, and means for including the same in circuitwith the meter when the storage battery is connected with thecharging-machine to compensate for the removal of the saidelectromagnetic windings, substantially as described.

In witness whereof lI hereunto subscribe my name this 20th day ofNovember, A. D. 1901.

THOMAS DUNCAN. Witnesses:

SAMUEL R. BACHTEL, FRANK V. NELSON.

